Coccidioides immitis is the etiologic agent of the fungal disease coccidioidomycosis (San Joaquin Valley Fever). Infection in man and other animals usually occurs following inhalation of arthroconidia into the lungs. Disease may be evident after an incubation period of one to four weeks. Approximately 60 percent of those infections are asymptomatic or characterized by a self-limiting upper respiratory infection. The remaining 40 percent of infections proceed to the lower respiratory tract resulting in mild or severe pneumonia which may resolve spontaneously or progress to form pulmonary nodules or cavities, occasionally resembling tuberculosis or carcinoma. In rare cases, the infection may disseminate to almost any organ of the body, including the skin, bone and central nervous system. Recent increases in infections by fungal pathogens, including Coccidioides immitis have increased the need for a rapid and sensitive method of detection for Coccidioides immitis. See William A. Check, CAP Today, Aug. 1994, 1, 12-16.
Conventional laboratory identification methods used to identify C. immitis include culture on fungal media, growth rate, colony morphology, microscopic morphology, animal inoculation and biochemical tests. These tests may require long incubation periods and require additional confirmatory tests. Identification begins with culture of the specimen on fungal media. The time required for growth to a visible, cobweb-like colony varies from 3 to 21 days and the mature colony morphology varies. Additional growth is needed before the characteristic microscopic sporulation pattern of alternating arthroconidia may be seen. Many species of fungi other than C. immitis may produce similar colony and sporulation patterns, including such naturally occurring soil fungi as Malbranchea and Uncinocarpus spp. Some yeast-like organisms such as Geotrichum and Trichosporon spp. may also resemble C. immitis.
Animal inoculation is another method sometimes used to detect Coccidioides immitis by producing the species-specific spherules characteristic of Coccidioides immitis. Still other confirmatory tests based on exoantigen extraction have been described, but these tests may take 3 to 5 days or longer to perform.
None of the references herein are admitted to be prior art.